This disclosure relates in general to content delivery networks (CDNs) and, but not by way of limitation, to accelerating web page delivery for a CDN.
The speed users expect from web browsing is increasing. After requesting a web page, only a fraction of second can pass before a user presumes a web page is inoperative or lacking sufficient quality of service (QoS). Caching is used to speed delivery of certain web content, but that caching is largely ineffective for dynamic content that is changing frequently or has components that change. The best web sites are the most responsive from the end user's perspective.
CDNs have a geographically distributed network of points of presence (POPs) such that one is likely to be close to the end user. A request for content is matched to a nearby POP using routing, domain name service (DNS) diversion, redirection, Anycast and/or other techniques. An edge server in the POP will serve up the content from its cache, a host within the CDN or an origin server depending on where the content is located. For content that is missing from the CDN, the request to the origin server can be costly in terms of QoS because of delay and bandwidth costs.